Tuyere construction for stokers



Patented Nov. 25, 1924.

UNITED STATES PATENT OFFICE.

ROBERT A. FORESMAN, OF ESSINGTON, PENNSYLVANIA, ASSIGNOR TO XVESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

TUYRE CONSTRUCTION FOR STOKERS.

Application filed July 15, 1920.

T all yiti/0m 'it may concern.'

Be it known that I, ROBERT A. FonnsMAN,

a citizen of the United States, and a resident of Essington, in the county of Delaware and State of Pennsylvania, have invented a new and useful Improvement in Tuyre Construction for Stokers, of which the following is a specification.

This invention relates to mechanical stokers of the underfeed type wherein the fuel is supplied to the grate through retorts, and more particularly to the grate surface and tuyres thereof, and has for an object the production of side tuyres adapted to facilitate combustion of the fuel adjacent the side walls of the furnace and at the same time prevent the formation of objectionable clinkers.

Where the usual form of side tuyres is employed, the side walls of the furnace are unprotected from the intense heat adjacent the surface of the burning fuel, and consequently clinkers adhere to the heated side walls and accumulate so as to interfere with the combustion of the fuel issuing from the side retorts unless they are regularly removed. Such clinkers are usually dislodged from the `side walls by means of rams or pokers inserted through poke holes in the sides of the furnace. As it is necessary to forcibly jar the clinkers free from the walls by repeated ramming movements of the poker, permanent injury is done to the tire brick walls which necessitate shutting down 235 the furnace for repairs.

By replacing the usual flat side tuyeres with high tuyres which slope from a point adjacent the wall to the near side wall of the adjacent retort, the fuel is prevented from coming into contact with the re brick. The tuyres are constantly cooled by the air passing through them, and clinkers do not adhere thereto.

Another object of the invention is the production of side tuyres having the characteristics described above which may be economically and simply constructed and which may be readily assembled or replaced.

Another object is the production of side tuyres having the above described characteristics which may be applied to standard stokers employing flat stepped side tuyres, and which may receive air from the usual 4 side tuyre box and uniformly distribute it D to the fuel resting against the tuyeres.

Seriall No. 396,377.

Another object is the production of side tuyeres having ample cooling surfaces and facilities whereby overheating, warping, and cracking are prevented.

These and other objects are attained by means of a stoker construction embodying the features herein described and illustrated in the accompanying drawing forming a part hereof, wherein Fig. 1 is a. longitudinal-vertical section of an underfecd stoker taken through the center of a retort showing a side wall equipped with the improved side tuyeres; Fig. 2, a transverse section on the line II-H of Fig. l; Fig. 3, a vertical transverse section through a side tuyere shown in Figs. l and 2; Fig. 4, a rear elevation of a modified form of side tuy`ere plate; Fig. 5 a transverse section through the tuyere plate shown in Fig. et taken on line V-V of Fig. 4; Fig. is a view in section taken on line Vl-Vl of Fig. 3; and Fig. 7 is a sectional view taken on line VII-VII of Fig. 3.

Referring to the drawings, I have shown the improved form of side tuyeres applied to a well known type of underfeed stoker, but it will be understood that the side tuyres may be used effectively in stokers of other types. The stoker illustrated includes a fuel hopper 5 disposed adjacent the front wall G of the furnace and aligned with a fuel retortl T which is adapted to receive the fuel forced from the hopper by the reciprocating ram S.

ln the furnace illustrated, a plurality of retorts are employed which extend longitudinally of the furnace in parallel relation, and rows of tuyre plates 9 are arranged in stepped relation between the retorts. Fuel is forced out of the retorts by the `1ncoming fuel and spreads out over the tuyeres in a well known manner. Each retort is formed of a pair of spaced support members 10 which are connected by means of a bottom plate 11. rl`hc supports 10 of adjacent retorts are spaced apart so as to form a tuyre box 12 which is in open cornmunication with the air box 13 beneath the retorts. Tuyre plates 9 are supported upon the flanged upper edges of the supports 10 in stepped relation, and air is delivered from the tuyere box to the fuel bed through tuyere openings 13 provided in the top and bottoni faces of the tn vere blocks or plates.

Heretofore slokers have been equipped l SLS CTD? n...

with side tuycres similar in profile to the tuycres located between the retorts, such side tuyeres being supported upon a side tuyre.

cox 12 formed by a side support 10 and a support 1() of the :ufljacent retort. Such tuyeres do not prevent the fuel from coming into contact with the side walls of the furnace, and consequently clinlers form thereon in the manner previously described. In order to olwiate this difficulty, I have provided side' tuyeres 15 disposed between the side retort 'i and the furnace side wall 1G and adapted to be mounted upon the standard supports l and 1f). These tuyeres li'orm, in effect, a continuation of one side of the side retort and project above the normal level ofthe fuel bed adjacent the side wall so as to prevent the `hot. fuel from coming in contact with the sidewall. l

As shown in Figs. 2 and 3, each side tuyre includes a rear or back-plate 1T aiflapted to fit snugly against the side wall 16 and rest upon the upper flange of the support member and a front or tuy`ere plate 18 which rests upon the support member 10 of the side retort and is inclined toward the side wall. rThe upper flanges of the supports 10 and 1() are provided with notches 19 and 19 into which portions of the plates 17 and 1S Afit respectivelyso as to prevent the plates from moving longitudinally of the supports. The lower extremities of the plates 17 and 18 are provided with flanges 20 and 2O which project under the upper flanges of the supports 10 and 10, respectively, the flanges serving to hold the plates 1T and 18 against vertical dis* placement.

The tuy`ere plates 18 form, in effect, a continuation of the retort side wall and arc spaced from the back-plates 17 so as to pro-` 22 provided between the lower edges of the plates. The air is discharged to the fuel adjacent the tuyere plates through a series of tuyere openings 2?) distributed over the face of the plates and adapted to direct the air into the fuel bed. rflhe tuyre openings may be of any suitable form, but are preferably elongated as shown in Fig. a.

In order to prevent excessive preheating of the air passing to the upper portion of the tuyres in order that the temperature of that section may be maintained.relatively low by the cooling action of the air, cach tuyre plate is provided with an integral diaphragn'i2ll: extendingupward from the bottom of the plate to a point substantially midway between the top and bottom thereof. Air entering the chamber 21 must pass to the top of the tuyere before it is delivered to the opening in the lower portion thereof. The diaphragn'i serves also as a healv conducting or cooling flange or web.

laisses he cooling action of the air supplied to the tuyeres is sufficient to prevent excessive heating of the tuyres and thus prevents the formation of clinkcrs which cannot accumulate upon the cool surface thereof. llteferring to Fig. 3, it will be seen that tuyere plate 18 is provided with webs which serve as stilfening and heat conducting webs.A

In Figs. a and f3 I have illustrated a modi- .fied form of tuyere plate 18 which is similar to the plate just described with the exception that the heat conducting and cooling members comprise a series of inwardly projecting conical lugs 2G around which theA air circulates before passing through the tuyere openings 23. A variety of forms of cooling surfaces may be employed without departing from the spirit of the invention.

`While I have described andillustrated but two embodiments of my invention, it will be apparent to those skilled in the art that various changes, modifications, additions, and omissions may be made in the apparatus without departing from the `spirit il t) and scope of the invention as set forth by the appended claims. lllhat I claim 1s: 1. In a Stoker for furnaces,r the combination of support members defining a furnace L side-wall `air box `adapted to receive air un der pressure and having opposed. horizontal flanges withnotched portions, a back-'plate supported by the support member adjacent the furnace sidewall and having depending flanges extending beneath the notched portions of its support member, and a tuyre plate having depending flanges at its lower edge extending beneath the notched portions of its supporting member flange and having its upperside resting againstlthe upper side of the bacleplate.v

2. In` a stoken for furnaces, the combina tion of support members defining a. furnace side wall air box adapted to receive air under pressure and having opposed horizontal flanges with notched portions, a back plate tion of support members defining a furnace side wall air box adapted to receive air runder pressure and having opposed horizontal flanges with notched portions, a back plate supported by the support member adjacent the furnace side wall and having depending lill) flanges extending beneath the notched portions of its support member, a tuyre plate having depending flanges at its lower edge extending beneath the notched portions of its supporting member flange and having its uppei` side resting against the upper side of the back plate, and a baffle plate extending upwardly parallel to the tuyre plate.

4L. In a Stoker for furnaces, the combination of support members defining a furnace side wall air box adapted to receive air under pressure and having opposed horizontal flanges with notched portions, a back plate supported by the support member adjacent the furnace side wall and having depending flanges extending beneath the notched portions of its support member, a tuyre plate having depending flanges at its lower edge extending beneath the notched portions of its supporting member flange and having its upper side resting against the upper side of the back plate, a battle plate extending upwardly substantially parallel to the tuyre plate, and ribs connecting said baille plate and tuyre plate.

In testimony whereof, I have hereunto subscribed my name this l2 day of July, 1920.

R. A. FORESMAN. 

